var GameObjectsFactory = function () {
    this.createBackground = function () {
        throw "The createBackground() method has not been implemented.";
    };
    this.createPlayer = function () {
        throw "The createPlayer() method has not been implemented.";
    };
    this.createEnemies = function () {
        throw "The createEnemies() method has not been implemented.";
    };
    this.createMapObjects = function () {
        throw "The createMapObjects() method has not been implemented.";
    };
};